Roller Chain Sprocket Bore Diameter 1 7/8 in For Chain Pitch 1 in For Number of Strands Single Hub Type One Side Material Steel Maximum Bore Diameter 1 7/8 in Number of Teeth 18 Outside Diameter 6.27 in Pitch Diameter 5.759 in Bore Type Fixed Chain Number 80 Finish Black Oxide Hub Diameter 4 1/4 in Hub Projection 0.925 in Includes Set Screws Keyway Yes Keyway Width 1/2 in Length through Bore 1 1/2 in Number of Set Screws 2